Based on research performed at the University of Pennsylvania on a Phospho-Energetics, Inc. (P-E) NMR spectrometer for the "Validation of 31p in Diseased and Normal Human Tissues", P-E has developed a combination NMR/work output measuring instrument. Studies have been performed with subjects suffering from peripheral vascular disease, genetic defects, cardiomyopathy as well as normal volunteers and athletes leading to a data base from which the ratios of various phosphates, e.g., phosphocreatine/inorganic phosphate (PCr/Pi), phospho diesters/Pi, and sugar phosphates/Pi etc. may be used to determine the state of tissue. It is proposed to extend this work into a study of "apparent" normal volunteers between the ages of 65 and 75 to try and correlate the existing data with ongoing measurements relative to an exercise protocol and nutritional protocol. In order to do this, it will be necessary to develop a new non magnetic linkage suitable for in magnet leg exercise. It is expected that the combined 31P NMR, non magnetic linkage and ergometer could become commercially important as a screening test to 1) identify incipient PVD or diabetes and 2) to evaluate the effect of exercise and the relationship between exercise and nutrition in the aging population.